Audiphone rheostat and switch.



K. B. HASTINGS.

AUDIPHONE RHBOSTAT AND SWITCH.

APPLIOATION FILED APR .13, 1911.

Patented Feb. 20, 1912.

2 SHEETS-SHEET l.

K. B. HASTINGS.

AUDIPHONE RHEOSTAT AND SWITCH.

APPLIGATION FILED APR.1s,1911.

1,018,856. Patented 11611.20, 1912.

2 SHEETS-SHEET 2.

UNITED sTATEs 4PATENT OFFICE.

KENNETH B. HASTINGS, OF BOSTON, MASSACHUSETTS, ASSIGNOR T0 GLOBE EAR-PHONE v COMPANY, 0F BOSTON, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

AUDIPI-IONE RHEOSTAT AND SWITCH.

To all whom it may concern:

Be it known that I, KENNETH B. HAS- TINGs, a. citizen of the United States, and resident of Boston, in the county of Suffolk and State of Massachusetts, have invented an Improvement in Audiphone Rheostats and Switches, of which the following description,in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

This invention lrelates to a combination rheostat and switch, which, while applicable to other and more general uses, is especially designed for use with portable telephone apparatus of the type adapted to be carried about by persons of defective hearing to augment and clarify the sounds of conversations, etc. In this type of apparatus it is highly desirable that a currentcontrolling means be employed in the telephone Icircuit since the batteries used deliver a much ygreater current when new orfresh than after a period of use; further, the amount of current required varies considerably with different persons of various degrees of deafness and withvthe same per-` son vas he becomes more accustomed tothe use of the device. It is also necessary that a disconnecting switch be provided to entirely shut off the current when the device is not in use so that the battery may not be quickly worn out. Thus, a rheostat and disconnector switch are requisites of the apparatus and, in these devices, it is essential that'all the working parts be made as small and simple in construct-ion as possible so that the whole mechanism may not be unwieldy and cumbersome to the user.

My invention therefore provides an improved combination disconnector switch and' rheostat with a construction that can be brought within very small compass, while operating with perfect certainty to perform its functions and being at the same time of an attractive design and convenient to manipulate. V

The invention will stood from the following detailed description, taken in connection with the accompanying drawings, vand will thereafter be .pointed out in the appended claims.

l -Referring to the drawings, Figure 1 -is a plan view, approximately actual size, ofv

my improvedy device; Fig. 2 is an elevation Specification of Letters Patent.

Application filed April 13, 1911.

be more fully under-- .hand one o Patented Feb. 20, 1912.

Serial No. 620,875.

of the interior mechanism removed from the shell; Figs. 3 and 4 are left and right end elevations respectively of the parts shown in Fig. 2; Fig. 5 is a plan View of the 'same parts; Fig. 6 is an enlarged front view of the device with the casing shell broken away to better show the interior construction; Fig. 7 is a plan view ofal modified form of the invention; Fig.'8 is an enlarged central longitudinal section thereof; Fig. 9 is a transverse section on the line 9 9, Fig. 8; Fig. 10 is a front elevation showing the interior parts of this form removed; Fig. 11 is a plan View of the parts shown in Fig. 11; and Fig. 12 is a plan of an insulating shell.

Referring to Figs. 1 to 6, a tubular shell 1 is provided to receive a generally cylindrical block 2 of vulcanite, this typlfying any suitable hard insulating material. The tubel or shell 1 has its ends closed except for the wire openings 3, 4 in any suitable manner,

the left-hand end in Fig. .l being shown` at 5 as spun over to rounded form, an annular shoulder being provided as a backing for the block 2. Theother tube-end'ma-y' be closed by a removable cap 7 tted thereinto, this cap having, as shown, ashoulder 8 interitting with the end of thetube to form a smooth joint. The block 2 has a groove 9 formed along-its top, and cut out portions 10, 11 at its ends. Its lower portion is also cut out through most of the length thereof, as shown at 12, and the ends are also cut away at the bottom -`as at 13, 14. A series of metallic pins, shown as seven in number, are driven transversely through the block 2, the middle ones 15 of these pins projecting through into the cutl out rec'ess 12 almost to the circumferential line ofthe cylindrical block 2, as shown at 16. The right hand pin 17 is shorter than the others and has con-v nectedthereto one circuit terminal 18. A coil of fine Aresistance wire 19 is wound Varound the projecting pins 15, one end of this wir'e being connected, to the post 17 of terminal 18` and contacts being made to the successive posts 15 to include progressively increasing portions of the coil 19, the leftthe otherend of the coil '19 so that, when `contact is made through this post, the entire A left-hand resistance coil is in circuit. p1n20 of the'serles 1s llkewlse cutoff short the posts l5 being connected to v 2 rolas@ of theothers and this is dead, having no circuit connection so that, when the movable contact rests thereon, the circuit is disconnected. A longitudinal slot 21 is formed in 5 the shell 1 of a length to include the project-` ing tops of the entire row of pins 15, 17, and 20. A movable contact button 22 slidable over the slot on the outside of the tubular shell has a shank 23 extending through said slot and a metallic leaf-spring contact 24 secured thereto and adapted to press upon the interior of the tube'and upon any one of the pin-head contacts over which it may be positioned, thus making reliable contact between the metallic shell and a pin-head with which it is engaged. Grraduations, which may be suitably. distinguished', are formed opposite the respective contact posts on the tube adjacent the slot so that the proper position of the contact button for vany desired strength of current can be instantlyr ascertained. A line terminal is connected` with the metallic shell by soldering or friction ressure, as shown at'26. The 25 current throug the apparatus is therefore under the control of the slidable button 22; when this button is moved to its extreme l left, as shown, resting upon the dead contact ypin, 20, the circuit is entirely broken. As it ismoved toward the right to engage with the first pin 15, a relatively small current is delivered, beingV required to pass through the entire resistance of coil 19. As the button is moved progressively to the right over l the succeeding pins 15, the resistance 41s gradually cut out until, as it rests upon the right-hand pin 17, the circuit isv entirely freed from theV resistance 19 and the'maximum current is delivered. It is desirable in devices of this kind that lthe return circuit cord also be connected with the switch, so

that the parts present a vneat appearance and are convenient for handling, and to this end a rod or stout wire 27 is assed lengthwise through the block 2 out oi) contact with thel several pins and other conductive elements, and the terminals 28, 29 of the return conductor are soldered or' otherwise fastened thereto at the two projecting ends 30, 31 of said wire. Y

In the form of the invention shown in Figs. 7 to 12, a tubular shell 32, similar` to the shell 1, with a spun-over end 33 and wire-receiving opening 34,`may be employed and a closure cap 35 tted to the other end as in the other form. In this form of the invention, likewise, the rheostat and switch mechanism are preferably carried by a hard insulating composition, and in this case the vulcanite or other substance for this ur'- pose 1s formed in an outer shell 36 tted within the metallic tube and having a widel lengthwise slot 37 adapted to register with a longltudinal slot 38 of the metallic tube.

The resistance coil and the lrheostat and switch contacts are in this case carried by an inner vulcanite shell longitudinally divided vinto an upper half 39 and a lower half 40, vthis being of a size to fit within the outer vulcanite shell 36. The upper half 39 of 70 this shell is cut away for most of its length at both its sides where it engages the other shell half as shown at 41, so that when th two halves of the shell are fitted together, opposite lengthwise openings are provided thereinto. A series of metallic contact pegs are fixed in lengthwise alinement to the top half 39, the two at either end 42, 43 being extended as pins down through the hollow `of the shell, and around these projecting 80 ends is wound a fine resistance wire coil 44. One of the wire terminal connections to the device shown at 45 is connected to the pin peg 43, and one end of the resistance coil 44 is also connected thereto. The successive intermediate contact pegs 46 are connected with the successive parts of the resistance coil winding by having the wire brought up through the side grooves 41 past the sucl cessive contacts as shown at 47, and the t other end of the coil is connected with the left hand pin `peg 42. A dead peg 48 is ,fixed to the shell portion 49 at the left of the pin 42 and shown as spacedtherefrom correspondingly to the spacing of the other pegs, A button 49 is slidable f along over the tube slot l38 on the outside of the tube, witha shank 50 extending through the slot and carrying a metallicleaffspring contact 51 pressing between the interior of the shell and any one of thecontact pegs over which itmay be positioned and thus making circuit connection therebetween. The other line terminal to the device is shown at 52v and is brought into contact with the metallic tubular shell at 53. Thus,-when the button 49 is moved to the extreme left, aso' shown in Fig. 8,v the circuit is disconnected. When it is moved one step to the right to engage the Contact peg 42, current will pass through' 110 theentire resistance'coil 44 and be correspondingly reduced to a minimum. As the button is moved to the right to engage the successive pegs 46, successive-portions of the resistance coll are cut out until, when'the' button is moved to the extreme right and enf gages the pin peg 43, the resistancey is en' tirely cutout and a maximum current is permitted to be delivered. In this'case, likewise, the return wire is arranged to pass through the switch, this being accomplished by providing grooves 54,55 in the shell'portion v39 from the ends of thel cut out part, 41 to the endsl of the shell, -so that the return wire 56 may have a passageway through the device. Y

By the arrangement of parts described in both forms o f my invention, it is -to be observed that acombination rheostat and disconnector switch is provided which is ca- 1.30

pable of performing its functions perfectly and With certainty and which can be formed in very small dimensions, While the tubular form with lengthwise' slidable button makes a ydevice neat and attractive in appearance and convenient to manipulate. The entire device is composed of a small number of parts which can be quickly assembled, requiring no screws or special fastenings, and the Wire cord connections can be readily att-ached to the projecting contacts at either end without any particular skill being required for the assemblage.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

l. A device of the kind described, comprising a metallic tubular shell having connection to constitute a circuit terminal, an insulating block fitted Within the same and carrying spaced apart contacts constituting the other circuit connection, and a contact button slidable along said shell to make contact and complete the circuit from the same to any of said contacts, said button extending Without the shell for direct hand operation.

2. A device of the kind described, comprising a metallic shell constituting a circuit connection, an insulating block fitted Within the same and having-a plurality of spacedapart contacts extending lengthwise thereof to form the other circuit connection, and a button slidable in a lengthwise slot of said shell and adapted to complete the circuit fromsaid shell to any one of said contacts at option, said button extending Without the shell for direct hand operation.

3. A device of the kind described, coinprising a metallic shell connected to a line terminal, an insulating block iitted Within -said shell, a series of spaced-apart contacts extending lengthwise of said block, a resistance coil carried by said block and having diiferent parts connected tol said seriesof l contacts and connectedat one end to the other line terminal, and a contact button slidable along a slot in said shell and adapted to make contact from the shell to any one of said resistance-connected contacts or to a iinal contact to cut out all of said resistance.

4. A device of the kind described, comprising a metallic shell having an extended longitudinalslot, an insulating block fitted Within said shell and having a series of spaced-apart contacts fixed to said block and connected to different parts of a resistance coil, and a button carrying a spring contact slidable along said slot and engageahle with any one of said contacts.

5. A device of the kind described, comprising a metallic shell constituting a circuit connection, an insulating block Within said shell and having transversely fixed thereto a series of spaced-apart contacts, said for completing the circuit from said shell toany one of said contacts at will.

6. An apparatus of the kind described,

comprising a metallic tubular holder constituting a circuit connection,l an insulating block fitted Within said holder and having a plurality of spaced-apart contacts, a resistance coil connected at separated points in its length to the several contacts, and means operable from the outside of said holder for making' connection therefrom to any one of said contacts at Will.

7. A device of the kind described, comprising a metallic holder constituting a circuit connection, an insulating member carried thereby and holding a circuit connected contact in spaced-apart relation to said metallic holder, and a slidable spring member adapted to simultaneously press upon said metallic holder and upon said contact to complete the connection therebetween, said member being slidable therefrom to disconnecting position.

8. A device of the kind described, comprising a metallic shell constituting a circuit connection, an insulating member held therein and carrying aseries of spaced-apart contacts, circuit connection to said-contacts in-l outside of the shell for completing the cire..

cuit therefrom to any one of said contacts, said member being also movable to disconnecting position.

9. A device of the kind described, comprising a metallic tubular shell havingv a spun-over end With a cord-receiving opening and having a cap closure for its other end, an insulating block insertible in said shell and carrying a series -of spaced-apart contacts, a resistancecoil connected` at separated points to the several contacts, and a slidable member for completing the circuit from said shell to any one of said contacts at Will and movable also to disconnecting position.

10. A device of the kind described, comprising a metallic tubular shell having a spun-over end with a cord-receiving opening and having a cap closure for its other end, an vinsulating block insertible in said shell and carrying a series of spaced-apart contacts, a resistance coil connectedat sepa.

rated points to the several contacts, a slidable member for completing the circuit from said shell to any one of said contacts at Will and movable also to disconnecting position,

and a return conductor extending through said block and projecting from its ends to receive line connections.

11. A device of the kind described, comprising an 'nolosing shell of electrically conductive material having` connection to oonstitute a o1rcu1t termlnal, an 1nsulat1ng memcomplete the circuit from the same to any oi:s 10 said spaced apart contacts at Will. 0

ln testimony whereof, I nave signed my ber fitted Within the same and Carrying name to this specification, in the presence of 5 spaced apart contacts, said contacts having connections to constitute the other circuit terminal, and a Contact member movable along the shell in constant i engagement therewith and adapted to make Contact and tWo subscribing Witnesses.

KENNETH B. HASTINGS.

Witnesses: y

CLYDE L. ROGERS, EDWARD Alt/JAXWELL. 

